Talk:Glucose

Sources of Glucose

I propose moving the Production section under "Sources" and describe where glucose is found and how it is made. Any comments. Codwiki (talk) 21:22, 8 December 2009 (UTC)

Historical terms: Commerical Glucose-Corn Syrup, and Commercial Dextrose-Corn Sugar

Working with WikiProject Grocer's Encyclopedia, I found historical terms Commercial Glucose, Corn Syrup, Commercial Dextrose, Corn Sugar [[1]] (search for those terms). Would someone be able to incorporate the information found there into the article. I believe the information would be out of date, but it would interesting to add the history of sugar manufacturing and/or vocabulary used in the 1910's. Onionmon 16:38, 28 December 2006 (UTC)

I second this. There should be more info in the article about the commercial, industrial and "everyday" (as found and used by the consumer) uses of dextrose. I came to the article looking precisely for that info and could not find any info. 24.83.178.11 13:08, 5 May 2007 (UTC)BeeCier

Dubious photos

The photos which are meant to be of "glucose" and "glucose tablets" look more like they are of white chocolate! They need to be replaced with proper photos of glucose, please. 137.205.29.128 04:06, 28 February 2007 (UTC)

Glucose is supposedly inside your blood cells, and it forms cellulose Structure Glucose (C6H12O6) contains six carbon atoms, one of which is part of an aldehyde group. Therefore glucose is an aldohexose. In solution, the glucose molecule can exist in an open-chain (acyclic) form and a ring (cyclic) form (in equilibrium). The cyclic form is the result of a covalent bond between the aldehyde C atom and the C-5 hydroxyl group to form a six-membered cyclic hemiacetal. At pH 7 the cyclic form is predominant. In the solid phase, glucose assumes the cyclic form. Because the ring contains five carbon atoms and one oxygen atom (like pyran), the cyclic form of glucose is also referred to as glucopyranose. In this ring, each carbon is linked to a hydroxyl side group with the exception of the fifth atom, which links to a sixth carbon atom outside the ring, forming a CH2OH group. Glucose is commonly available in the form of a white powder or as a solid crystal. It can also be dissolved in water as an aqueous solution. Its solubility level is very high. Isomers Aldohexose sugars have four chiral centers, giving 24 = 16 stereoisomers. These are split into two groups, L and D, with eight sugars in each. Glucose is one of these sugars, and L-glucose and D-glucose are two of the stereoisomers. Only seven of these are found in living organisms, of which D-glucose (Glu), D-galactose (Gal) and D-mannose (Man) are the most important. These eight isomers (including glucose itself) are related as diastereoisomers and belong to the D series. An additional asymmetric center at C-1 (called the anomeric carbon atom) is created when glucose cyclizes and two ring structures called anomers are formed as α-glucose and β-glucose. These anomers differ structurally by the relative positioning of the hydroxyl group linked to C-1 and the group at C-6, which is termed the reference carbon. When D-glucose is drawn as a Haworth projection or in the standard chain conformation, the designation α means that the hydroxyl group attached to C-1 is positioned trans to the -CH2OH group at C-5, while β means that it is cis. An inaccurate but superficially attractive alternative method of distinguishing α from β is observing whether the C-1 hydroxyl is below or above the plane of the ring; this may fail if the glucose ring is drawn upside down or in an alternative chair conformation. The α and β forms interconvert over a timescale of hours in aqueous solution, to a final stable ratio of α:β 36:64, in a process called mutarotation.[3] The ratio would be α:β 11:89 if it were not for the influence of the anomeric effect.[4] The Fischer projection of the chain form of D-glucose The chain form of D-glucose α-D- glucopyranose β-D- glucopyranose Chain form: ball-and-stick model Chain form: space-filling model α-D- glucopyranose β-D- glucopyranose Rotamers within the cyclic form of glucose, rotation may occur around the O6-C6-C5-O5 torsion angle, termed the ω-angle, to form three rotamer conformations as shown in the diagram below. In referring to the orientations of the ω-angle and the O6-C6-C5-C4 angle, the three stable staggered rotamer conformations are termed gauche-gauche (gg), gauche-trans (gt) and trans-gauche (tg). For methyl α-D-glucopyranose at equilibrium the ratio of molecules in each rotamer conformation is reported as 57:38:5 gg:gt:tg.[5] This tendency for the ω-angle to prefer to adopt a gauche conformation is attributed to the gauche effect. Rotamer conformations of α-D-glucopyranose Production Natural 1. Glucose is one of the products of photosynthesis in plants and some prokaryotes. 2. In animals and fungi, glucose is the result of the breakdown of glycogen, a process known as glycogenolysis. In plants the breakdown substrate is starch. 3. In animals, glucose is synthesized in the liver and kidneys from non-carbohydrate intermediates, such as pyruvate and glycerol, by a process known as gluconeogenesis. 4. In some deep-sea bacteria glucose is produced by chemosynthesis. Commercial Glucose is produced commercially via the enzymatic hydrolysis of starch. Many crops can be used as the source of starch. Maize, rice, wheat, cassava, corn husk and sago are all used in various parts of the world. In the United States, cornstarch (from maize) is used almost exclusively. Glucose Glucose tablets Function Glucose metabolism and various forms of it in the process. -Glucose-containing compounds and isomeric forms are digested and taken up by the body in the intestines, including starch, glycogen, disaccharides and monosaccharides. -Glucose is stored in mainly the liver and muscles as glycogen. -It is distributed and utilized in tissues as free glucose. Scientists can speculate on the reasons why glucose, and not another monosaccharide such as fructose (Fru), is so widely used in organisms. One reason might be that glucose has a lower tendency, as compared to other hexose sugars, to non-specifically react with the amino groups of proteins. This reaction (glycation) reduces or destroys the function of many enzymes. The low rate of glycation is due to glucose's preference for the less reactive cyclic isomer. Nevertheless, many of the long-term complications of diabetes (e.g., blindness, renal failure, and peripheral neuropathy) are probably due to the glycation of proteins or lipids. In contrast, enzyme-regulated addition of glucose to proteins by glycosylation is often essential to their function.[citation needed] As an energy source Glucose is a ubiquitous fuel in biology. It is used as an energy source in most organisms, from bacteria to humans. Use of glucose may be by either aerobic respiration, anaerobic respiration, or fermentation. Carbohydrates are the human body's key source of energy, through aerobic respiration, providing approximately 3.75 kilocalories (16 kilojoules) of food energy per gram.[6] Breakdown of carbohydrates (e.g. starch) yields mono- and disaccharides, most of which is glucose. Through glycolysis and later in the reactions of the citric acid cycle (TCAC), glucose is oxidized to eventually form CO2 and water, yielding energy sources, mostly in the form of ATP. The insulin reaction, and other mechanisms, regulate the concentration of glucose in the blood. A high fasting blood sugar level is an indication of prediabetic and diabetic conditions. Glucose is a primary source of energy for the brain, and hence its availability influences psychological processes. When glucose is low, psychological processes requiring mental effort (e.g., self-control, effortful decision-making) are impaired.[7][8][9][10] [edit] Glucose in glycolysis α-D-Glucose Hexokinase α-D-Glucose-6-phosphate D-glucose wpmp.png Glucose-6-phosphate wpmp.png ATP ADP Biochem reaction arrow foward YYNN horiz med.png Compound C00031 at KEGG Pathway Database. Enzyme 2.7.1.1 at KEGG Pathway Database. Compound C00668 at KEGG Pathway Database. Reaction R01786 at KEGG Pathway Database. Use of glucose as an energy source in cells is via aerobic or anaerobic respiration. Both of these start with the early steps of the glycolysis metabolic pathway. The first step of this is the phosphorylation of glucose by hexokinase to prepare it for later breakdown to provide energy. The major reason for the immediate phosphorylation of glucose by a hexokinase is to prevent diffusion out of the cell. The phosphorylation adds a charged phosphate group so the glucose 6-phosphate cannot easily cross the cell membrane. Irreversible first steps of a metabolic pathway are common for regulatory purposes. As a precursor Glucose is critical in the production of proteins and in lipid metabolism. In plants and most animals, it is also a precursor for vitamin C (ascorbic acid) production. It is modified for use in these processes by the glycolysis pathway. Glucose is used as a precursor for the synthesis of several important substances. Starch, cellulose, and glycogen ("animal starch") are common glucose polymers (polysaccharides). Lactose, the predominant sugar in milk, is a glucose-galactose disaccharide. In sucrose, another important disaccharide, glucose is joined to fructose. These synthesis processes also rely on the phosphorylation of glucose through the first step of glycolysis. [edit] Industrial use In the industry glucose is used as a precursor to make vitamin C in the Reichstein process, to make citric acid, gluconic acid, bio-ethanol, polylactic acid, sorbitol. Sources and absorption Most dietary carbohydrates contain glucose, either as their only building block, as in starch and glycogen, or together with another monosaccharide, as in sucrose and lactose. Crystalline fructose, for example, does not contain glucose and is about ninety-eight percent fructose. In the lumen of the duodenum and small intestine, the glucose oligo- and polysaccharides are broken down to monosaccharides by the pancreatic and intestinal glycosidases. Other polysaccarhides cannot be processed by the human intestine and require assistance by intestinal flora if they are to be broken down; the most notable exceptions are sucrose (fructose-glucose) and lactose (galactose-glucose). Glucose is then transported across the apical membrane of the enterocytes by SLC5A1, and later across their basal membrane by SLC2A2.[11] Some of the glucose is directly utilized as an energy source by brain cells, intestinal cells and red blood cells, while the rest reaches the liver, adipose tissue and muscle cells, where it is absorbed and stored as glycogen (under the influence of insulin). Liver cell glycogen can be converted to glucose and returned to the blood when insulin is low or absent; muscle cell glycogen is not returned to the blood because of a lack of enzymes. In fat cells, glucose is used to power reactions that synthesize some fat types and have other purposes. Glycogen is the body's 'glucose energy storage' mechanism because it is much more 'space efficient' and less reactive than glucose itself. History Because glucose is a basic necessity of many organisms, a correct understanding of its chemical makeup and structure contributed greatly to a general advancement in organic chemistry. This understanding occurred largely as a result of the investigations of Emil Fischer, a German chemist who received the 1902 Nobel Prize in Chemistry as a result of his findings.[12] The synthesis of glucose established the structure of organic material and consequently formed the first definitive validation of Jacobus Henricus van't Hoff's theories of chemical kinetics and the arrangements of chemical bonds in carbon-bearing molecules.[13] Between 1891 and 1894, Fischer established the stereochemical configuration of all the known sugars and correctly predicted the possible isomers, applying van't Hoff's theory of asymmetrical carbon atoms. See also * Blood glucose or Blood sugar * HbA1c * DMF (potential glucose-based biofuel) * Glycation * Glycosylation * Photosynthesis * Fructose * Beriberi - vitamin deficiency affecting ability to convert carbohydrates into glucose * Sugars in wine * Trinder glucose activity test * Glucose transporter (GLUT): GLUT1, GLUT2

an erased portion

if you look under PRODUCTION it starts with how the body, or plants, produce glucose befor using it. Then it starts in the middle of no where explaining an industrial method of glucos production. It sounded interesting but where's the start of it.

I've put the missing paragraphs back in K.murphy 11:32, 15 June 2007 (UTC)

Is L-glucose sweet?

Is L-glucose sweet? and if so can it make you fat?

I googled "L-glucose taste" for you and came up with this article. According to it, there is no difference in taste between L- and D-glucose, it also won't make you fat because the body can't metabolize L-glucose, so someone thought of the idea of using it as a low calorie sweetner, unfortunately according to the article its very hard to synthesise in the large quantities needed. K.murphy 21:33, 4 June 2007 (UTC)

What happens if you inject it?

What happens if you inject it? will you get lots of energy

If your blood glucose levels are low before you inject it then you might feel more energetic. However, your body tries to keep your blood glucose levels under tight control. Too much glucose is bad for you and so is not enough glucose. People who can't keep their blood glucose levels under control suffer from a disease called diabetes. K.murphy 14:10, 7 June 2007 (UTC)

Production section error

Part of the Production section seems to have been erroneously deleted, as there is a heading for natural production in photosynthesis, gycogenolysis, and gluconeogenesis, but no industrial/laboratory synthesis heading. Also, the paragraph following the listing of natural formation processes begins with discussion of the second step of an industrial synthesis process.

I found the missing paragraphs and reinstated them. They where deleted in an edit on the 1st January at 19:55 K.murphy 11:32, 15 June 2007 (UTC)

The MOST IMPORTANT CARBOHYDRATE ON BIOLOGY?

Saying that glucose is "the most important carbohydrate" is VERY subjective and not something that should make it into an encyclopeadia. So, I'll be removing that.

It's like defining "dog" as "man's best friend". Not for a serious encyclopeadia!!

OK, I Couldn't Do It but Someone Else please DO! I tried deleting "the most important carbohydrate" but for some reason there is only an "edit" for the second entry and I just don't know how to edit the first. There's GOTTA be a way, though. So someone who knows how to do it please delete that! We are in WIKIPEDIA for God's sake, not in a First Grade report on glucose or carbohydrates!

I'll change it to "an important carbohydrate", is that better? K.murphy 20:11, 20 June 2007 (UTC)

Um... glucose is the critical sugar for life; lack of this would be rapidly fatal, the brain requires it, the muscles burn mainly glucose for energy; and are largely incapable of burning other sugars like fructose. I don't really see that this is subjective. It's present in comparatively vast quantities; and the entire insulin axis senses glucose; I could go on.WolfKeeper 10:57, 8 August 2007 (UTC)

Try living without ribose ;) Mattert 02:23, 5 January 2008 (UTC)

I add to Mattert and say that you should also try living without deoxyribose. Come back to me when you manage to get genes without it, and then we'll discuss it.

--mast3rlinkx (talk) 22:46, 14 December 2009 (UTC)

Why does grape sugar direct here?

http://en.wikipedia.org/wiki/Grape_sugar

Grape sugar directs here, yet the article mentions nothing about grape sugar. Why does one article direct to another when there is not apparent relation between them? —Preceding unsigned comment added by 71.7.147.153 (talk) 22:07, 29 September 2007 (UTC)

I second this question. Grapes are not unusually high in glucose as compared to fructose, are they? Fundamentisto (talk) 00:27, 17 July 2008 (UTC)

Grapes, as far as I know, have more fructose than glucose, I will say that. However, "grape sugar" is a term commonly used in place of glucose, so therefore, it makes sense for "grape sugar" to redirect you to this article.
--mast3rlinkx (talk) 22:19, 14 December 2009 (UTC)

Need information on L-glucose

The article marginalizes L-glucose on the basis that the body can't ingest it, giving it only a one-sentence mention. This is kind of unencyclopedic. I think a subsection needs to be added on L-glucose. Unfortunately most of the references I'm googling up are medical mumbo-jumbo like "temperature dependence of the enantioselective adsorption of D- and L-glucose on a chiral Pt{643}S electrode", which I can't decipher well enough to work into the article. -Rolypolyman 13:29, 18 October 2007 (UTC)

All of the physical and chemical properties of L-glucose (with the exception of optical rotation) will be the same. Apart from this difference and the fact that L-glucose is neither made nor used in any biological processes, what else are you looking for? We could mention its potential use as an artificial sweetener and how it could be made see [2] Silverchemist 14:26, 18 October 2007 (UTC)

Thanks. The differences do extend beyond physical properties. L-glucose has its own unique history, synthesis process, and owing to the difference in biological processing I'm sure it has been studied for use as an artificial sweetener. I did find L-glucose was synthesized in 1889 by E. Fischer. -Rolypolyman 17:56, 18 October 2007 (UTC)

Glucose is the prtical of energy and has many storing and helping particals that can help you move and even help you turn the chanel on the tv. —Preceding unsigned comment added by 64.8.139.121 (talk) 18:33, 26 October 2007 (UTC)

Incorrect IUPAC name

I think the assignment of chirality centres is incorrect. RSRR is correct sequence in the chain form but in cyclic it changes, The correct name should be: (2R,3R,4S,5S,6R)-6-(hydroxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrol for β-form and (2S) for α-form Mjackas (talk) 15:44, 6 January 2008 (UTC)

GLUCOSE

IS GLUCOSE AROMATIC OR NON AROMATIC? IS GLUCOSE SATURATED OR UNSATURATED? WHAT IS GLUCOSE(ALDEHYDE,AMINES.....)? —Preceding unsigned comment added by 117.196.133.11 (talk) 13:54, 17 June 2008 (UTC)

WikiProject Food and drink Tagging

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structure

The structure image show only five carbon atoms! Glucose has six, so the structure is wrong! 193.137.16.74 (talk) 16:06, 25 September 2008 (UTC)

The structures in the article are correct, with all six carbons. The skeletal formula article may help with interpretation of this type of chemical structure drawing. -- Ed (Edgar181) 16:18, 25 September 2008 (UTC)

When D-glucose is drawn as a Haworth projection or in the standard chain conformation, the designation α means that the hydroxyl group attached to C-1 is positioned trans to the -CH2OH group at C-5, while β means it is cis. An inaccurate but superficially attractive alternative method of distinguishing α from β is by observing whether the C-1 hydroxyl is below or above the plane of the ring;

This is supposed to be the opposite way. Correct it. Peace —Preceding unsigned comment added by 122.172.122.238 (talk) 03:08, 17 January 2009 (UTC)

Sorry, the current version has alpha/beta described correctly--Glycoform (talk) 14:46, 17 January 2009 (UTC).

2D image of glucose in the infobox

The 2D image of glucose is wrong. It should show that the OH group on Carbon 1 is anomeric (because it can be both equatorial or axial).

The image at the top of the infobox is currently showing the beta-D-glucopyranose anomer. It's not incorrect... it's just not showing both structures in one spot. Occasionally the anomeric carbon will have a bracket next to it with -OH and -H, indicating that the structure can be the alpha or beta anomer. The beta anomer is arguably more common in nature, so it makes sense to show it at the top of the article. But perhaps a more succinct label is in order... Fuzzform (talk) 22:46, 4 May 2009 (UTC)

I agree with Fuzzform(talk), the most common form arguably should be displayed, since it's the one people will most likely run into.

--mast3rlinkx (talk) 22:35, 14 December 2009 (UTC)

Structures.... again

Apparently there has been a great deal of confusion as far as the various structures of glucose are concerned... While all the structures shown in the various images are correct, they are randomly scattered throughout the article. This makes it difficult to find the structure being described in the text at any given point. What is needed is a clear diagrammatic representation of the interconversion between the straight chain form (Fischer projection) and the alpha and beta cyclic pyranose forms. (An example of what I'm describing can be found in McMurry: Organic Chemistry, pg.985.) Also apparently absent from the article are the Haworth projections. I'm rather surprised that such an important article is so disorganized... why hasn't this become a featured article yet? Perhaps because it's rather confusing for the average, non-technical reader. Clarifying the structural interconversions will hopefully make the article much less confusing.Fuzzform (talk) 22:42, 4 May 2009 (UTC)

Archae is not a protist.

I am not good at editing Wiki's. It is just sort of baffling, so I prefer to NOT leap in and change stuff and make the article look like crap...

BUT, Archae is not considered a prokaryote any more. There are now considered 3 super kingdoms. Those are Prokaryotes, Eukaryotes, and Archae. Archae have characteristics of both Eukaryotes and Prokaryotes.

Now, how you want to incorporate this into the article I don't know. Maybe change it to say Bacteria, Archae, Plants, Animals, etc etc. I would just hate for this article to not be up to date in thinking that Archae is still considered under the category of a prokaryote. It is NOT a prokaryote even if it lacks a nucleus etc. There are about 7 major characteristics that divide prokaryote from Eukaryote and Archae is split between the two on its characteristics.

I know it sounds like a stupid dinky factoid and splitting hairs, but it does make Wikipedia sound ignorant and I hate for that to be the case. I love this place and I want to do what I can to make things as factual as possible.

One other thing, I think this is the smallest possible sugar. There might be one other than can compete with this sugar for smallest, but this sugar has a special place in being the building block of higher sugars like sucrose etc.

Thanks for your time and consideration. Please do what you can to get things all cleaned up. —Preceding unsigned comment added by 98.66.202.45 (talk) 04:17, 11 November 2009 (UTC)

You do have a point. Archae are different from prokaryotes, but the title of this section doesn't make sense. You said that Archae is not a protist, then went on to talk about the previous misunderstanding that Archae are prokaryotic. Why? Protists are eukaryotic, so why didn't you argue that Archae aren't eukaryotes? And about what you said about glucose being the smallest sugar is simply not true. There are several sugars that are smaller, like deoxyribose, or ribose. The two smallest sugars are dihydroxyacetone and glyceraldehyde. The chemical formulas for both of those is C₃H₆O₃. I hope this clears up what you said and corrects any mistakes you made. If I made any mistakes, feel free to correct them, but I shan't think that I did, as I used actual Wiktionary and Wikipedia articles.

--mast3rlinkx (talk) 22:33, 14 December 2009 (UTC)